1)
What do we learn from "Asher Gar ha'Ger Ito"?
1.
Rashi (from Koheles Rabah 1:18): He converted in Galus amidst that Shevet. Malbim ? his portion will be amidst that Shevet.
2.
Radak: When Yisrael leave Galus in the future, the Shevatim will be known. Even though now they are mixed, and a man does not know his Shevet, Eliyahu will tell everyone which Shevet he is from 1 .
1
Radak agrees that the verse teaches that a convert will receive in the Shevet amidst which he converted. He infers that Bnei Yisrael will properly inherit according to their Shevatim.